panorama

His EV battery poised for a comeback, does Edison have new currency for the renewables age?

As the proliferation of renewables has undergone its inevitable rise and fall and rise again in recent years, it has become fashionable to point to the geniuses of the past both as advocates (or questers) for the technology and as wise, ancient voices urging the trend forward. Perhaps no one gets this treatment more that America's most famous inventor, Thomas Alva Edison. He is an easy choice.

Not only was he one of a handful of men born in the 19th century who ushered in the modern age -- and was the one most responsible for the widespread consumption of electricity -- but throughout his career he returned time and time again to technologies that are today seen as being at the forefront of sustainability.

For instance, in 1912 Glenmont, Edison's New Jersey home for the last 44 years of his life, was dubbed the "Edison Twentieth Century Suburban Residence”, having been taken completely off the grid and receiving its power from a bank of 27 rechargable batteries in the basement.

According to a 12 September 1912 article in The New York Times, the home was crammed with all manner of electric luxuries available at the time, including air conditioning, a washing machine, an electric range and, his most commercially successful invention, incandescent light bulbs.

The batteries were charged by a gas-run motor, but more recent articles suggest Edison planned to hook the whole thing up to a wind turbine. That plan wasn't original -- another inventor, Charles Brush had actually created a wind-powered house in Cleveland, Ohio in 1888 -- but Edison hoped to find a way to bring the idea to the masses.

As he told The Atlanta Constitution in 1901, "With a windmill coupled to a small electric generator" a homeowner could store enough electricity in a battery to provide reliable light at night.

It's not clear why he never took the plan further -- his own home was eventually connected to the grid -- but he clearly never shook the notion that renewable sources of power were something that should be tapped into.

Famously, shortly before his death from diabetes and kidney failure in 1931, the prolific inventor is known to have told his friends Henry Ford, founder of the Ford Motor Co., and Harvey Firestone, the tire magnate, "I'd put my money on the sun and solar energy. What a source of power!" adding, "I hope we don't have to wait until oil and coal run out before we tackle that."

While Edison's bona-fides in the world of renewables and sustainability would therefore appear beyond misinterpretation, it's wrong to suggest his motivation for embracing these concepts is similar to our own, according to Leonard DeGraaf, archivist for the Thomas Edison National Historical Park in West Orange, N.J.

"I think the idea that Edison was interested in renewable energy in the same sense that many of us are, in terms of environmental reasons, is probably not an accurate portrayal," DeGraaf said during a recent interview that culminated in a lengthy tour of Edison's extensive laboratory complex.

"It’s not the same sensibility. He is interested in different types of energy, and in harnessing the most cost-effective forms of energy, but based on the evidence we have here, I don't think Edison really thinks like an environmentalist or from an environmentalist's perspective, if that makes sense," he continued.

DeGraaf, who is currently writing a book about Edison, acknowledges the inventor's statements about solar power. He also mentions comments Edison made at various times regarding his concern that oil and gas will eventually run out.

In 1913, for instance, Edison told Scientific American magazine that he believed "The possible exhaustion of the world's oil supply deserves the gravest consideration."

"[But] that doesn't mean he's an alternative energy guy the way we might define that today," DeGraaf said. "For Edison, tapping into nature's energy potential is a practical thing."

"He has the idea that oil and gas are not infinite resources, but I think the prevailing view -- especially for an industrialist like him -- was that resources in nature are resources available for people to use.

"Maybe it's too fine a distinction, but Thomas Edison doesn't really spend time researching renewable sources of energy. He is interested in power, in all its forms. For instance, we know from his paper that he has an idea for extracting power directly from coal, but he never really -- as far as I know -- explains how he would do that," DeGraaf said.

The practical inventor

The archivist's bottom line is that Edison considered himself a 'practical inventor,' one who conceived and created score upon score of society-altering inventions, but did so, ultimately, with an eye toward marketing them to the masses.

In that context, one of the most 'green' things Edison did, by the modern definition, was his work on the electric vehicle battery.

Initially, the evidence suggests Edison was dubious about the potential for creating an electric automobile. In 1895 he told a reporter -- you may note, he's always talking to reporters -- that while it was obvious the car was going to replace the horse, he doubted that an electric vehicle was in the offing because the storage batteries that existed at the time simply were not compact or reliable enough to be used to power them.

However, just four years later, in 1899, Edison evidently had a change of heart and decided he was going to tackle the problem.

"This is not surprising," DeGraaf explained. "Edison had always been interested in batteries, having relied on them from the very beginning of his career."

In his early years working in a telegraph office, and at his first laboratory, in Menlo Park, N.J., Edison relied on a crude technology called a primary battery.

In a primary battery the electrolytes that provide the power are consumed in the process of making it and need to be renewed. They can't be recharged. Storage batteries, which first became available in the 1860s, could be recharged, but were nowhere near as reliable as the batteries they were intended to replace.

Further, because they were made of lead and acid, they were heavy and dangerous and more costly to maintain, so not practical for powering electric vehicles.

Edison had used primary batteries in the 1870s and 1880 to power his experiments on the electric light bulb and a host of other projects. When he began working on storage batteries in a serious way in 1899, his goal was to strip out the lead and the acid, and, ultimately, to bring a better product to market.

"It's a point in time when the question of whether cars would be powered by gasoline, steam or electricity still hadn't been resolved yet, and you might say, the upside was huge," DeGraaf said. "By 1900, and despite the limitations of the batteries available, about 30 percent of the automobiles manufactured in America are electric."

"But Edison doesn't manufacture electric cars himself, rather he relies on the car manufacturers to design and sell cars that use his batteries," the archivist said. "Ultimately it takes him 10 years to come up with a battery, using nickel and iron, that he was willing to sell and let consumers buy. It eventually comes out about 1910."

There is evidence that a few car makers -- the Baker Electric Co., definitely, and perhaps Studebaker and others -- used the Edison Battery, by the time the inventor becomes fast friends with Ford, in 1913, the industrialist most associated with the development of the assembly line technique of mass producing automobiles, the pioneering development of the electric car battery is already past.

As everyone knows, the internal combustion engine ultimately won the battle of the 20th century marketplace, but Edison's battery might just be poised to win the war after all.

In just the past month, researchers at Stanford University announced they believe Edison's century old break-through may just hold the key to electric cars finally reclaiming their place as a mass market vehicle.

Edison's advantage is the charge and release time of the nickel-iron chemistry. While Edison's battery never dominated the automobile market -- during the more recent explosion of interest in electric cars, the battery's storage capacity was greatly surpassed by other formulations -- its value was proven and second life ensured by wind turbines and solar arrays, technologies seemingly tailor-made to take advantage of its fast storage and release capabilities.

In the latest issue of Nature Communications, a team of Stanford researchers led by chemistry professor Hongjie Dai put forward the notion of coupling a small Edison Battery -- which can be recharged in minutes -- with a larger, longer to charge lithium-ion battery found in many current EV models.

By combining them, the researchers suggest shorter trips could be taken relying on the very fast recharging of the Edison Battery, while longer excursions could be facilitated by the lithium-ion battery.

In their version of the Edison Battery, the researchers bonded the electrodes to carbon nanotubes and to a sliver of graphene, a super-material made of carbon.

"Coupling the nickel and iron particles to the carbon substrate allows electrical charges to move quickly between the electrodes and the outside circuit," Dai said in a written statement. "The result is an ultra-fast version of the nickel-iron battery that's capable of charging and discharging in seconds."

Edison's first laboratory

To most people, Thomas Edison was, and will forever be, "The Wizard of Menlo Park," the inventor of the incandescent light bulb, the phonograph and the motion picture camera, and the patriarch of the both the recording and movie industries.

To get a true sense of the man and to put whatever ideas he had and/or acted on in terms of renewables, Renewable Energy Magazine visited the sites of his two main laboratories, at Menlo Park and West Orange, N.J. in late June.

While at the latter, we spoke extensively with DeGraaf about what are perhaps Edison's greatest legacies to innovators of all stripe, the ideas behind how his laboratories themselves function, and how he went about branding himself as not a creator of new technologies, but as their trusted commercial purveyor.

But first there was the rude shock of Menlo Park (Pictures of the site, as well as the Edison's West Orange Lab can be found on REM's Facebook page).

Having driven up U.S. Highway 1 in Central New Jersey, we turned off the crowded thoroughfare at the small suburban town of Metuchen and then followed the signs past bagel shops, delicatessens and Italian restaurants to a quiet neighborhood just north of town.

Turning onto tree-lined Christie Street, it was a drive of only two short blocks when we came upon a grass covered corner lot dominated by a large stone tower.

The Art Deco tower, in such disrepair that it was surrounded by a chain link fence, was topped with a large ceramic light bulb. A few feet away stood the modest, one-room Thomas Edison Center at Menlo Park, which stood locked and closed, despite a sign saying it was open.

The tower itself stands exactly on the site of the wooden two-story structure in which a then unknown Edison created the world's first industrial research facility in 1876 and did his pioneering work on the phonograph (1877) and the light bulb (1879).

In the corner of the lot, distinguished by an historic marker, is the brick outline of the foundation of Edison's office. The sign tells how Edison often entertained potential financial backers in the building and even welcomed the likes of financier J.P. Morgan and the actress Sarah Burnhart.

Somewhere beneath the soil and grass that filled the foundation is the vault in which Edison kept his most important papers and inventions safe from prying eyes. These no doubt included the results of another series of experiments with magnetic gold ore separation that paved the way for the development of the vacuum tubes later used in radio and television.

The natural temptation, which we indulge, is to walk the edges of the foundation and then to walk right on through the foundation rectangle -- "to walk where Edison walked" while nudging fragments of the original bricks with the toe of our shoe along the way.

There are few places one can stand on a spot where events that happened there definitively changed the world, and this is one of them. Yet the solitude of the corner lot is a remnant of a different story.

Like many tech and energy entrepreneurs of our day, Edison's professional activities essentially boiled down to a two act play -- he would invent the future, then promptly found a company to commercialize it.

In one failed attempted to do just that, Edison experimented with and actually developed an electric railroad.

"It doesn't really go anywhere [as a business]," DeGraaf said. "But it shows he immediately understood that consumers are only going to need electric light at night, and so the question from his standpoint is, 'What are you going to sell the rest of the day?'"

Flush with money from the success of the incandescent light bulb and earlier improvements to telegraph technology, Edison relocated home and office to New York City in 1881, and builts the first permanent central power station in Lower Manhattan.

By the time Edison returns to the Menlo Park site, in the 1920s, his laboratory and office are in ruins.

"There was a preservation sensibility, and the family, by this time, realizes Edison's work is important and wants to preserve it, but the real catalyst for doing anything along those lines was Henry Ford, who wanted to move these and other historic buildings to a place called Greenfield Village, which was actually part of an American innovation museum he was building in Dearborn, Michigan," DeGraaf said.

"It's kind of an interesting statement on the mind of Henry Ford, because here he was one of the guys responsible for building 20th century America, but he's nostalgically trying to collect all these 19th century buildings and preserve them," he added.

Ford removed as much of the original building material as he could from the site, and faithfully rebuilt the structures with the aid of photographs.

In 1937, six years after Edison's death, the surviving employees of the Menlo Park lab formed an organization called the Edison Pioneers, and erected the tower. The small museum was added a decade later.

A new start

By the time Edison returned to New Jersey to establish his elaborate laboratory complex in West Orange, he'd been widowed, remarried, and soon began work the kinetograph, an early version of the movie camera, the kinetoscope, a boxlike device with which to view motion pictures, and refinements to the phonograph.

At the same time, he embarks on an ultimately failed quest to establish a commercial ore milling industry, and a more successful venture producing cement.

For all this, when we finally meet DeGraaf for the first time in person next to the employee time clock in the main laboratory building -- a clock permanently set to the time that Edison left the building in his casket -- he offered what some would take as a surprising observation.

"My own opinion -- and this may change, but for right now -- I think [Edison's] most successful innovations were the laboratories, and I say that because with the laboratories he creates environments that bring together all of the things that you need to be innovative on a regular basis," he said.

"In other words, with these laboratories, he's able to make the invention process much more reliable and predictable," he continued. "The reason that’s important is because the people who have the money to invest and to support the operation of a laboratory and support new technologies are more likely to help somebody like Edison, who has an ongoing research laboratory and a track record, than a lone inventor who is just kind of out there and may have a good idea once in awhile.

"Edison, by creating the laboratories and bringing in trained experimenters, the best tools and the best knowledge and information that he can get, improves the odds of coming up with more innovations on a regular basis," DeGraaf said.

A few steps away from where the archivist is speaking is what can easily be described as the brain and nerve-center of the lab, Edison's office and library, which starts on the ground floor and rises another two stories -- just enough to hold the 10,000 books and periodicals housed on its neat, hardwood shelves.

"This room was intended to impress and it does; it was a statement about who he was," DeGraaf said as he stood near Edison's desk. "It's the most ornate room of the laboratory, being where he displays his awards, trophies, photographs of his friends and mementoes, and it's also the center of his business operations, where he would manage all of the companies that he creates to manufacture and distribute his inventions."

Gesturing to the rows and rows of books, DeGraaf goes on to explain that as part of the innovation process, Edison and his lab workers were constantly gathering information from the wider world, relying on some as the basis of creating new technologies, using others -- like the annual bound volumes Edison received from the U.S. Patent Office -- to keep tabs on what was being invented elsewhere.

"Edison read a lot over the course of his lifetime. We know this because he liked to underline things and write things in the margins of what he read. We also know from archival documents that he had accounts at all the big book sellers of the time," he said.

"In this way," DeGraaf continued, "Edison is also the beneficiary of a change in society."

"We often talk about today being the information age, but really, it was the 19th century that was the beginning of that," he said. "Because of the nature of what Edison does, he needs access to this scientific and technical information and also commercial information. He needs to know what’s going on out in the economy, and he needs to know what’s going on with the consumers to whom he hopes to sell his product."

"I think one of the fascinating things about standing in this room, is it gives you a sense of what the entire laboratory was all about," DeGraaf said. "On the one hand you have the library and at the other end you have the power plant that supplies the heat and the electricity, and it’s these two things, the information and the new technology, that are kind of symbolic of what’s going on in the laboratory itself."

At this point, we talk about DeGraaf's book, which he says will likely be published early next year.

"It's an attempt to focus on Edison as an innovator and not solely as an inventor," he said. "I mean, we all recognize Edison as this prolific inventor who turned out all these new things; what's less appreciated by most people is that he was doing more than solving technical problems.

"He's engaged in a wide range of activities related to innovation -- the manufacturing, marketing, promotion, raising capital, educating consumers, educating the investors... there's a whole other body of activity going on that I think often gets ignored."

"The other interesting thing about Edison is that he brands himself in the process, and he's probably one of the first business leaders in the country to do that as a way to promote his inventions," DeGraaf said.

When it was suggested his description sounds like it could also be applied to the late Steve Jobs of Apple, DeGraaf said he's heard that comparison a lot.

"I'm not sure where I come down on that question, but I'm sure we could probably do a week's seminar just unpacking that whole notion," he said.

"But that aside, I think what makes Edison's story relevant is the questions he had to answer in developing new types of products in his day are the same kinds of questions innovators in energy, technology or any other area have to answer today," he said.

DeGraaf admitted the book project has been a challenge for multiple reasons, one being because Edison involved himself in so many things.

"The other reason it’s complicated is Edison’s not the same innovator throughout his career," he said. "He changes over time. When he starts out as an inventor in the 1870s, working on improvements to the telegraph, he’s very young and inexperienced, and his approach to innovation and his strategy… well, let's just say he’s in a learning mode… so he’s making more mistakes. As he gets more experience, you start to see him get better and more mature -- one example of that being he does of better job of choosing who to work with later on."

"So if you talk about Edison as an innovator, you have to remember that he’s changing, and the environment he’s working in is changing all the time as well," he said. "Society itself is undergoing profound changes during the years Edison is working. We see the emergence of a mass consumer market in the late 19th and early 20th century, and mass circulation advertising, companies are starting to operate in national markets as opposed to local and regional markets, and this is all going on while Edison is active and he has to kind of adapt and work in this environment as it changes."

The magic of a 'big junk pile'

Down the hall from Edison's library/office, one begins to appreciate the scale of the inventor's activities. The balance of the first floor is given over to a heavy machine shop, while the entire second floor is given over to a precision machine shop and rooms set aside for distinct experimental activities.

Three other buildings make up the permanent laboratory complex, the most noteworthy today being Edison's chemistry lab, which is periodically open to visitors. At the height of Edison's activities, more than 200 people were employed here, although the number varied depending on the project at hand.

But before we get to any of this, we stop at an area defined by shelves and cabinetry that is partitioned from the hallway by a tall metal fence.

"This isn't a park service security measure," DeGraaf said of the fence. "Thomas Edison himself had it put in to create a stock room."

"Edison had a saying about inventing, he said, the secret to inventing is having a big junk pile," DeGraaf said. "When he opens the laboratory in 1887 one of the first things he does is sit down with a bunch of catalogs and he makes lists of all kinds of stuff to buy.

"A lot of it was common everyday things, like different kinds of metal stocks, screws, things like that, but there are also some more exotic things, like different kinds of animal horn, abalone -- there were no plastics then -- different kinds of animal skins, rabbit felt, that kind of stuff.

"He also had another saying, he liked to say his laboratory had everything from the hide of an elephant to the eyeballs of a U.S. Senator," DeGraaf said.

Motioning to a large, thick piece of hide on the table, he adds, "We actually do have elephant hide right here, but we haven’t found the eyeballs yet."

"One of the things that's so interesting about the stock room is it illustrates how he has to draw upon the natural world to invent things; another thing is what it says about his strategy of inventing. He wants to make the invention process as efficient as possible. He has this stuff on hand because if they are working on any idea, and someone says, 'Why don’t we try a piece of elephant hide, maybe it'll will work,' he doesn’t have to wait to get it.

"It’s a question of bringing into the laboratory as much of the different kinds of resources he can to be prepared to invent efficiently," DeGraaf said.

Revolutionary ambiance

To step into the heart of Edison's laboratory complex is to truly step back into the early days of the industrial revolution. Organized in two, roughly parallel rows, heavy, black machines dominate the long, rectangular room.

The machines operated off two massive drive-shafts which were powered by two large DC motors at the far end of the room.

If a worker needed to use one of the machines, he would move a belt attached to it onto the rotating drive-shaft from its neutral position, thereby drawing power to his location. Whether there was one or 20 workers in the room, the process was the same, DeGraaf said. Even a lone worker would have to turn on the power to the motors, and set the huge drive-shafts turning if he wanted to work.

When it was ventured that this wasn't the most energy efficient approach to powering a factory that we'd heard of, DeGraaf was unfazed.

"It's what Edison had available at the time," he explained.

Anyway, far more interesting was the use of both the heavy- and precision-machine shops. Workers in these rooms not only turned out the proto-types for various inventions, they were also often tasked with manufacturing the machinery that would later be used in the numerous factories that sprung up around the lab to mass produce its products.

(All of these factories are now gone, the victims of time, fire and finally, urban renewable.)

Making our way to the second floor, DeGraaf explains that downstairs (in the heavy machine shop), you might do pieces to builds a locomotive; up here (entering the precision machine shop), you do work for making a watch or a phonograph."

"But here," he says, the tenor of his voice rising slightly, "is kind of a special area."

We're standing in the far end of the second floor, in the hallway outside a series of individual experimental rooms. This is where Edison and his key staffers could work on projects more or less privately.

"This is good place to bring up this point: To appreciate what you see here today you have to understand that this was a working laboratory. In wasn't a static place, and its configuration changed as Edison's needs changed," DeGraaf said.

"If Edison needed to build a temporary building or room, he would do that; then, when the experiment was done, they'd take it all down. All in the interest of continuing the innovation process. But that poses a challenge to the Park Service, in terms of how we interpret that story," he said. "Something important happened here, but we really don't know how to represent it because he didn't leave it. That wasn't his concern."

A case in point was just a few feet away, where a modestwall partially obscured a primitive camera and lighting setup.

"This is our recreation of one of those temporary rooms," DeGraff said. "From photographs taken at the time, we know this location is where the motion picture camera was developed... In a sense, you can say the birth of the motion picture industry happened right here. But he moved on to many other things and the space wasn't left intact."

A short distance away, across from a drafting room where plans and measured drawings of inventions were prepared, stands room 12, Edison's private experimental room.

"As you can imagine in a building like this, Edison was constantly interacting with staff; this is the one place he could go and just kind of close the door and work on whatever he's working," DeGraff said as we walked inside.

A photograph just inside the doorway shows Edison standing in a far corner, in front of a work bench and shelves lined with small bottles of chemicals.

"The only hard evidence we have to tell us what this room looked like is this photograph and we'd like to interpret this space better," DeGraff said.

But it's here that one finds Edison's batteries on display, a progression in battery science depicted in a neat row on an otherwise bare table.

"He spent a lot of time on the storage battery here in West Orange, and it was a big part of the business of the company, becoming a practical source of power for delivery trucks, lighthouses, railroad signals, boats and even miner's lamps," DeGraff said.

Because the room and the photograph are such an exact match, it was impossible not to imagine that Edison was still standing at the corner, his eyes falling upon an unexpected visitor. Taking in his appearance from the photograph, it was also hard not to notice he's got large, bleach-like stains on the front of his otherwise very formal-looking dark pants.

"He was probably wiping his hands on his pants as he was working with the chemicals," DeGraff said. "That's the kind of guy he was; he's hands on. In fact, we have pictures of his hands and... they're filthy with whatever he was working with at the time."

Dealing with the mass consumer market

Today the third and final floor of the laboratory is mostly used for open storage of thousands of inventions. It's here that one sees the first phonograph and other groundbreaking inventions as well as hundreds of commercial products ranging from a jukebox and collection of Christmas lights to coffee makers and waffle irons.

The third floor also contains the laboratory's music room, where Edison and his staff spent countless hours developing sound recording technology.

"After working on the electric light for a number of years, Edison goes back to the phonograph and develops it into a commercial product to be mass marketed," DeGraaf said. "As a result, this room is one of the earliest recording studios, and it's where a lot of the technical problems with recording sound are worked out."

Later on, Edison, who was partially deaf, would use the room as a place to evaluate recorded performances and decide whether or not to release them. Surviving notebooks reveal the exhaustive detail with which he evaluated them.

But when the entire story of the activities that grew from the room was told, it revealed one of the rare failures of inventor's career.

Edison spent hours evaluating performances because, then as now, it was difficult to predict what the music-buying public was going to want.

Edison's competitors, particularly the Victor Talking Machine Co., adopted a strategy of recording celebrities like Enrico Caruso and Al Jolson, and then spending lavishly for advertisements in the mass media of the day, capitalizing on the singers' pre-existing fame to appeal to potential record buyers.

Edison's would have none of that.

"He says, 'We're not going to spend that kind of money because we know our machines sound the best.' 'What we're going to do is try to get as many people as possible to listen to our phonographs, and once they hear it, they'll but it,'" DeGraaf said.

Among his schemes for carrying this out was having sales people go from house to house, dropping off phonographs and records for a free trials. After a couple of days they'd return to try to close the deal.

"The problem with this," DeGraaf said, "is that he's operating in a national market, but he's competing with local schemes, and he doesn't have the resources to expand these kinds of initiatives to a broader scale. So Victor comes out the winner, far surpassing Edison's reach."

DeGraaf believes that despite coming out a loser in commercial music -- Edison would cease manufacturing phonographs for entertainment purposes in 1929 -- his experience in this field tells an important story about mass marketing.

"This is not a criticism of Edison at all, but it shows him kind of struggling to deal with an emerging mass consumer market," he explains. "I mean, this a brand new concept, and that's the way it was.

"Edison does better with things like the storage battery and other technologies geared toward other manufacturers because he's used to working in that environment," DeGraaf said. "He's not as proficient with the consumer market because he doesn't understand it as well; it's just not how he does business."

While Edison does sell his storage batteries to consumers, DeGraaf said those batteries, "were not really a 'consumer technology.' It's really companies that prove to be their primary market, entities like Tiffany or Macy's, which are putting them in their delivery trucks."

And yet -- again shades of the future -- Edison is tantalizingly insistent on branding himself for disseminating his image far and wide.

Much of these efforts began in a photo studio that is also located on the third floor of the laboratory. It was here that the photograph of Edison that accompanies this article was taken, as we're literally thousands of other photographs of Edison and his inventions, some for in-house use and others, for promotional purposes. Today, the laboratory's archive bulges with some 60,000 historic photographs.

Edison was one of the first business leaders in America to trademark his image, name and signature. He would then use one or more of these in combination on his products as a sign of quality.

Why did he do this?

"That’s hard to answer," DeGraaf said. "I think he appreciates the value of having a good reputation and the role it plays in making him a successful innovator."

"By that I mean, he's not only trying to appeal to consumers, but also to people who have money that they might want to invest in his activities, people like J.P. Morgan and other investment bankers," he said.

"What we do know is that from a very early point in his career, Edison makes himself available to the press and cultivates good relationships with reporters, providing them with good copy and good stories," DeGraaf said.

"The other thing that he does create a reputation that his products are technically the best that are available, and then he makes sure his image and name are closely associated with those products, and that he stands behind them," he said.

"He's constantly using the laboratory and his reputation as an inventor as a way of promoting his products," he added.

Where invention left off and marketing began depended on the technology.

The standard story taught in American elementary schools is that Edison's first invention of note was an electric vote recorder that he patented in 1869, at just 21 years of age.

Edison was working in a telegraph office at the time, and his idea was to try to sell his invention to state legislatures to make lawmaking a more efficient process.

However, the young entrepreneur met with a harsh rebuttal from lawmakers, who flatly rejected the technology and said it would interfere with the deal-making that is part and parcel of the legislative process.

"This is a story Edison himself told many times, and it is important because, as he said, it made him realize it didn't make sense to develop technology that people don't want," DeGraaf said. "So when you read interviews that he gave to reporters, he’s always talking of himself as a practical inventor, meaning that he’s always paying attention to the market or what he thinks that market is."

Later DeGraaf would expand on his perception of Edison.

"The reason why Edison is a singular figure is not just that he creates these invention factories, but that he’s one of the first inventors to show corporate America that technological development can be a reliable process," he said. "Prior to that, investors was essentially asked to bet on a guy who might not have another good idea the rest of his life."

"What Edison does is create environments that make R&D kind of a routine thing. It takes somebody like Edison to demonstrate that new technologies can be part of a corporation's business strategy, and that's what really makes him stand out as an innovator," he said.

While some of suggested that Edison struggled with persona and that it eventually got away from him, DeGraaf disagreed.

"I think he’s sophisticated enough to know exactly what he’s doing when he’s dealing with the media, and he throughout is career she shapes his persona to suit his own purposes," he explained.

That said, DeGraaf admitted that Edison's purposes could sometimes be a little murky.

"One of the things that surprises me about Edison, and which I haven't quite figured out how to square, is that stories Edison himself tells about the laboratory and his work methods in interviews are markedly different from the reality of those things," he said. " Edison gives the impression that he has a very casual, no-rules approach to running the laboratory."

"For instance, in 1926, a member of the Industrial Research Council contacts Edison and says he wants to talk to him about his system for running the laboratory," DeGraaf said.

"Edison's response is, 'Well, we don't really have a system here, and you know, you're wasting your time, but if you want to come and hang out with me, that's okay.' He gives this impression of casualness in regard to innovation that the surviving evidence contradicts, because we can see that he spends a lot of time thinking about what he’s doing and he’s not at all casual about his work," DeGraaf said.

"I haven't figured that out yet. It appears this was very deliberate on Edison's part, but I really don't understand why he did that," he said.

"It's certainly an area we need to continue to explore," DeGraaf added.

With more than 5.5 million pages of archival documents, 400,000 artifacts, 48,000 historic sound recordings, 3,500 laboratory notebooks and 330 pocket notepads in the Park Service's possession, there certainly remain stones to overturn.

"I guess at this point the safest thing to say is that there are two Edisons for the purpose of this conversation," DeGraaf said. "The Edison who talks to the reporters is not the Edison that's in the laboratory doing the research... and I think that's why we continue to have discussions of whether or not he embraced things like solar power or renewable energy to this day: He often says things in public -- and to reporters specifically -- that don't necessarily mean he has an idea for something and that's he's actually working on it or will work on it.

"A lot of times, he just appears to be answering the questions reporters put to him, and in that context there's a possibility he's fooling with them and having fun," he continued. "The best example of that is an interview he gave in 1920 or 1921, where he starts talking about the possibility of inventing a machine that can talk to the dead.

"Now, it turns out that he kind of put his foot in his mouth in that case because it gets in the newspapers and people start sending him letters, pleading to buy one. There is no evidence he ever worked on any such thing. He was simply talking about a possibility... and I think it's same kind of situation with his statements on solar energy," DeGraaf said.

At the pinnacle

If Edison wasn't communing with the dead, he does have a Frankenstein of sorts tucked away in the back of his chemical lab to this day.

It's a remnant of Edison's last major project, the search for a domestic source of natural rubber, that he undertook with the backing of friends Ford and Firestone.

Beginning in 1927 and continuing until his death four years later, Edison and his staff tested over 17,000 latex-bearing plants, before finally settling on goldenrod, a common wildflower that typically grows to little more than three feet tall.

Through careful crossbreeding Edison was able to cultivate a plant that grew to 10 to 12 feet -- DeGraaf called it a "Frankenplant" -- and contained three times as much natural rubber that it did in its natural state. One of these plants remains in an open box in the chemistry lab, leaning against a far wall.

Though Ford continued to support the project after Edison died, the work was eventually rendered moot when scientists produced synthetic rubber from petroleum byproducts in the 1940s.

"We obviously think of Edison in the context of his work with electricity, but in reality his favorite discipline was chemistry and he was actually quite a good chemist," DeGraaf said, contemplating this portion of the laboratory.

"You know, the idea is not to make him out to be some kind of heroic figure, but his accomplishments are based on real talent. He's not a manufactured celebrity figure. He has abilities," he continued. "As much as he strove to brand himself, the one thing he dismissed was the notion that he was a genius.

"His famous line, of course was, 'genius is 99 percent perspiration and one percent inspiration,' and while I think he was oversimplifying a little bit, what he was saying basically is, it's a lot of hard work. He knows chemistry and electricity and all the other subject he works of because he works hard to collect all that information."

Locking the chemistry laboratory behind him as he stepped into the mid-day sun, DeGraaf stood in the yard between Edison's buildings and tried to put all he had spoken about and shown into perspective.

"Were there people in Edison's era that were just as talented as he was? Yes, I think there were," he said. "I think there's something going on. It's an inventive age. It is an entrepreneurial age. I mean, consider the fact that from roughly 1870 to 1930, all of the major technologies that come to define modern life come into being: airplanes, the electric power system, the electric light, motion pictures, automobiles, radio... and the reasons for this are complex.

"Part of it is that scientific advances in the 19th century allowed these inventors to apply that knowledge to new products, but there's also a lot of capital available," he continued. "The other thing is, entrepreneurs like Edison were willing to take risks."

As an example, DeGraaf cites Edison's extensive investment in a decades-long effort to create a modern iron ore milling industry in New Jersey.

"Edison invests his electric light money in the ore million project and it's a failure; he winds up losing the money, and somebody says, 'Mr. Edison, it's a shame you lost all your money on this.' His response is, 'Yes, but I had fun spending it,'" DeGraaf said. "For people like Edison, that was a prevailing attitude."

"I don't know how to say this without sounding jingoistic, I certainly don't mean it that way, but there is definitely something going on during that era, and Edison really is at the top of a community of inventors and entrepreneurs that are developing all these new technologies. He's not the only one, but he definitely stands at the pinnacle during that period," he added.